By a News Reporter-Staff News Editor at Electronics Newsweekly -- Investigators publish new report on Fullerenes. According to news originating from Ibaraki, Japan, by VerticalNews correspondents, research stated, "The gel separation of single-wall carbon nanotubes (SWCNTs) suspended in sodium dodecyl sulfate (SDS) is expected to be one of the most successful methods of large-scale and high-purity separation. Understanding the mechanism of the gel separation helps improve the quality and quantity of separation and reveals the colloidal behaviors of SWCNTs, which reflects their band structures."
Our news journalists obtained a quote from the research from the National Institute of Advanced Industrial Science and Technology (NIAIST), "In this study, we characterize the pH- and solute-dependent adsorption of SWCNTs onto agarose and Sephacryl hydrogels and provide a mechanistic model of the metal/semiconductor separation. The adsorbability of SWCNTs is substantially reduced under acidic pH conditions. Importantly, the pH dependence differs between metallic and semiconducting species; therefore, the adsorbability is related to the band-structure-dependent oxidation of the SWCNTs. Oxidation confers positive charges on SWCNTs, and these charges enhance the electrostatic interactions of the SWCNTs with SDS, thereby leading to the condensation of SDS on the SWCNTs. This increase in SDS density reduces the interactions between the SWCNTs and hydrogels. Under highly basic conditions, such as pH similar to 12.5, or in the presence of salts, the adsorption is dissociative because of the condensation of SDS on the SWCNTs through electrostatic screening by counterions. Desorption of the SWCNTs from the hydrogels due to the addition of urea implies a hydrophobic interface between SDS-dispersed SWCNTs and the hydrogels."
According to the news editors, the research concluded: "These results suggest that the metal/semiconductor separation can be explained by the alteration of the interaction between SDS-dispersed SWCNTs and the hydrogels through changes in the conformation of SDS on the SWCNTs depending on the SWCNTs' band structures."
For more information on this research see: pH- and Solute-Dependent Adsorption of Single-Wall Carbon Nanotubes onto Hydrogels: Mechanistic Insights into the Metal/Semiconductor Separation. ACS Nano, 2013;7(11):10285-10295. ACS Nano can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; ACS Nano - www.pubs.acs.org/journal/ancac3)
The news correspondents report that additional information may be obtained from A. Hirano, Natl Inst Adv Ind Sci & Technol, Nanosyst Res Inst, Tsukuba, Ibaraki 3058562, Japan. Additional authors for this research include T. Tanaka, Y. Urabe and H. Kataura.
Keywords for this news article include: Asia, Japan, Ibaraki, Fullerenes, Electronics, Semiconductor, Nanotechnology, Carbon Nanotubes, Emerging Technologies
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